Electric relay unit



Oct 24, 1950 B. E. @ETCHELL 2,526,361

ELECTRIC RELAY UNIT Filed Feb. 28, 1946 2 Sheets-Sheei: 3,

y 1 CI/VJL/LATIAII7 ATTORNEY Oct. 24, 1950 B GETCHELL 2,526,851

ELECTRIC RELAY UNIT Filed Feb. 28, 1946 A 2 Sheets-Sheet 2 B/METAL INVENTOR. IGLT/VJA AWN 5 GE 75 H5 1 L A TTORN V Patented Oct. 24, 1950 ELECTRIC RELAY UNIT Benjamin E. Getchell, Plainville, Conn., assignor to The Trumbull Electric Manufacturing Company, Plainville, Conn., a corporation of Connecticut Application February 28, 1946, Serial No. 650,896

My invention relates to protective devices and particularly to the type which controls a remote circuit. An unsafe condition in the main circuit which passes through the heater of the relay opens a switch in the control circuit. This switch will open automatically and may be adjusted so as to reset automatically or soas to permit manual resetting. The metal terminals and the switch controls and the insulating housing are so designed that the insulating housing can be easily molded and the metallic parts can all be inserted from one side or the other. The switch is released thermostatically to open the circuit upon an overload in the main circuit and may be readily calibrated by adjusting a bimetal strip and latch which releases the movable switch member. A resetting plunger normally permits the movable switch member to move out of range of the latch member, but by depressing and turning the plunger the switch member may be held in position so that the switch will automatically close the circuit upon cooling of the bimetal strip.

Fig. l is a side view of the body of the relay housing, the side plate being removed and the switch parts being shown in the normal on or closed circuit position.

Fig. 2 is a front or edge view of the entire relay device.

Fig. 3 is a side view of the parts of the relay involving my invention, the switch parts being shown in the tripped off or open circuit position. I

Fig. 4 is a similar view, the parts being in the tripped off position, ready for automatic resetting.

Fig. 5 is an enlarged view of a fragment of the housing showing the socket or bearing for the resetting plunger.

Fig. 6 is a fragmentary section of the resetting device on the line 66 of Fig. 4.

I Fig. 7 is a rear view of the housing and terminals.

Fig. 8 is an end view of the housing and terminals.

Fig. 9 is a plan and sectional view showing the bimetal member and calibrating device taken on the plane of the line 99 of Fig. 1.

Fig. 10 is a fragmentary sectional view showing the calibrating device.

Fig. 11 is an exploded perspectiveview of the thermostatically actuated switch member and its support.

Fig. 12 is an exploded perspective view of the latch or trip member of the switch and its support.

11 Claims. 7 (c1. 200 116) The housing of a single unit consists of the main body part l4 and the cover plate l5 held together for instance by screws Hi. The body part may have lugs M, M at opposite corners to facilitate mounting of such units on suitable foundations. The main circuit terminal plates l1 and I8 aresecured to the housing by bushings l9 and let into side recesses |9"and 20'. The terminal binding screws 2| and 22 are screwed through the plates I! and I8 and let into ,siderecesses 2| and 22.

A heater resistance 23 of any suitable type is connected to the terminal plates I1 and I8 by screws 24 and 25 which screw into the bushings I9 and 2|]. A bimetal strip 26 is carried by a resilient angle piece 21 which is supported by the housing beneath terminal plate l8. A rigid piece 28 is secured to piece 21 and a screw 29 is provided to calibrate the device by turning the screw against the slanting edge of the rigid piece 28 which thus bends the support 21 and changes the initial setting of the bimetal strip.

The housing is divided into two open chambers 30 and 3| by the insulating partition 32. The heater and bimetal strip are located sin chamber 30 and the switch mechanism is located in chamber 3|.

The switch has two binding screw terminal members 33 and 34 mounted at different levels on bushings 35 and 36 located in recesses 35 and 36. Terminal 33 is inserted through a passage 33 in the side of the end wall and terminal 34 is inserted in a slot 34' in the side of the end wall of the housing. The inner end of terminal 33 r rests on shoulder 31 and supports the switch member 38. A spring 39 mounted on the prong 40 biases the switch member to turn in an anticlockwise direction (as viewed in Figs. 1, 3 and 4). The switch member 38 is formed of sheet metal and its arm 38' is bent at approximately right angles. The other end of the switch member has the contact. 38". The central part of the switch member is cut out to form the prong 40 for the spring 39 and to provide slots 38;: to receive the notched part 33x of the terminal supporting member 33 on which the switch member is hinged or pivoted. The terminal supporting member 33 has an opening 35:0 for the bushing 35.

A latch member 4| is hinged to terminal member 34 and biased by spring 42 to turn in a clockwise direction against the tip 43 of the terminal member. The latch member 4| is formed of sheet metal and has a contact 4| at the end of one arm and an arm 45 bent at right angles to receive the thrust of the pin 44 and which is notched at Ma: to fit in the notches 34:1: of the terminal supporting member 34. The latter is formed of sheet metal and has a part stamped out to leave a prong 42.10 to support the spring 42. The tip 43 of the supporting member 34 acts as a stop for the latch member 4| when the latter is disengaged from the switch member 38.

An insulating thrust pin 44 is interposed between the movable end of the bimetal strip 26 and the lower arm 45 of latch member 4|. Normally the circuit is closed through the engagement of the contact tip 38" of the switch member 38 and the contact tip 4| of the latch member 4| as in Fig. 1. When the 'bimetal warps when heated, it pushes against pin 44 and disengages the latch member from the switch member so that the spring 39 tilts it about its pivot on member 33 away from the latch member. The switch member has an arm 38' which thus abuts against the inner end of a plunger 46 as shown in Fig. 3. This plunger slides in a passage in the housing and is pressed outwardly by spring 41, its outward movement being limited by its lug 4S striking against a shoulder 48. When the bimetal cools oft, the latch 4| will return to a latching position and the switch can be reset by simply pressing the plunger inwardly and tilting the switch member 38 back into the position of Fig. 1.

If it is desired to have the switch reclose automatically when the bimetal cools, it is only necessary to depress the plunger and rotate it clockwise .so that the lug 46 can travel in the camlike groove 49 and engage beneath the shoulder 50 (Figs. and 6). This holds the switch member in the position of Fig. 4 so that when the bimetal cools it permits the spring 42 to rotate the latch member back to engage the tip of the switch member and close the circuit. To return the switch to a manual reset condition, it is then necessary to rotate the plunger backward 180, release it and again depress it so as to relatch the switch member into the position of Fig. l.

I claim:

1. A relay com rising a housing, a supporting member in said housing having a circuit terminal, a switch member hinged to said supporting member and having a contact, a spring for bias ing said switch member and its contact to an open circuit position, a latch member having a contact to latch with the switch member contact in the on position, thermostatically actuated means for retracting said latch member from said switch member, a support for said latch member having a circuit terminal, said latch member being hinged to said support and biased toward the contact on the switch member, a manually operable spring retracted plunger in said housing coacting with said switch member to cause its contact to latch with the other contact, said plunger being rotatable and means for holding the plunger in against the switch member so that said latch member can automatically reengage said switch member.

2. A relay switch comprising a supporting terminal plate, a switch member hinged to said terminal plate and having two arms extending at substantially right angles to each other, a second terminal plate, a latch hinged to said latter plate and having two arms extending at substantially right angles to each other, one arm of the latch member coacting with one arm of the switch member, an o erload member coacting with the other arm of the latch member to retract the latch member from the switch member and a manually operable member coacting with the other arm of the switch member to reset it.

3. A relay switch comprising a supporting terminal plate, a switch member hinged to said terminal plate and having two arms extending at substantially right angles to each other, a second terminal plate, a latch hinged to said latter plate, and having two arms extending at substantially right angles to each other, one arm of the latch member coacting with one arm of the switch member, a thermostatically actuated thrust pin coacting with the other arm of the latch member to retract the latch member from the switch member and a manually actuated plunger coacting with the other arm of the switch member to reset it.

4. A relay having an insulating body containing coacting spring-pressed pivoted switch and latch members, a thermostatically actuated member for retracting the latch member and releasing the switch member to open the circuit, a spring-pressed resetting plunger slidable in a recess in the outer edge of said body and having a projecting lug, said body having a cam surface in said recess with which the lug of said plunger may be interlocked when rotated to hold the plunger in position to limit the release movement of the switch member and thus permit automatic closing of the circuit when the thermostatically actuated member cools off.

5. In an electric switch, a housing having a chamber, a terminal member supported at one end outside of said chamber and supported at its other end inside of said chamber, a spring-pressed switch member hinged to said terminal member and having two diverging arms with a contact at the tip of one arm, a manually operable spring retracted plunger operable in the housing to coact with the other arm for resetting said switch member, a second terminal member supported in said housing, a spring-pressed latch hinged to said latter member and having a contact coacting with the contact of said switch member and thermostatic means for retracting said latch from said switch member.

6. In an electric switch, a housing having a passage, a terminal member supported at one end outside of said housing and extending inside of said chamber, a spring-pressed switch member hinged to said terminal member inside of said housing and having two diverging arm with a contact at the tip of one arm, a manually operable spring-pressed plunger operable in said passage to coact with the other arm for resetting said switch member, means for holding said plunger in its depressed position, a second terminal member supported in said housingya springpressed latch hinged to said latter member and having a contact coacting with the contact of said switch member and thermostatic means for retracting said latch from said switch member.

7. In an electric switch, a housing having a chamber, a terminal member supported at one end outside of said chamber and its other end extending inside of said chamber, a spring-pressed switch member hinged to said terminal member and having two diverging arms with a contact at the tip of one arm, a manually operable springpressed plunger operable in the housing to coact with the other arm for resetting said switch member, a second terminal member supported in said housing, a springpressed latch hinged to said latter member and having a contact coacting with the contact of said switch member, thermostatic means for retracting said latch from said switch member and means for holding the plunger in position to ccact with said switch member and hold it in position to permit automatic resetting of said latch member.

8. In an electric switch, a housing having a passage, a spring-pressed. hinged switch member having a contact and an arm, a hinged springpressed latch coacting with said switch member, an overload device coacting with said latch to release said switch member, a spring-pressed plunger reciprocable and rotatable in said passage and coacting with the arm of the switch member for resetting said switch member, said passage having two shoulders spaced apart from each other in the direction of reciprocating and rotary movements of said plunger for limiting the movement of said plunger.

9. In an electric switch, a housing having a passage, a spring-pressed hinged switch member having a contact and an arm, a hinged springpressed latch coacting with said switch member, an overload device coacting with said latch to release said switch member, a spring-pressed plunger reciprocable in said passage and coacting with the arm of the switch member for re setting said switch member, said passage having two shoulders spaced apart from each other in the direction of reciprocating movement of said plunger for limiting the outward movement of said plunger.

10. In an electric switch, a housing having a passage, a terminal plate, a spring-pressed switch member hinged to said plate and having a contact and an arm, a second terminal plate, a spring-pressed latch hinged to said second plate and coacting with said switch member, an overload device coacting with said latch to release said switch member, a spring-pressed plunger reciprocable in said passage and coacting with the arm of the switch member for resetting said switch member, said passage having two shoulders spaced apart from each other in the direction of reciprocating of said plunger for limiting the outward movement of said plunger, one of said shoulders holding said plunger in position to permit automatic relatching of the switch member.

11. An electric switch construction comprising an insulating housing, two separate electro-conductive members, each having a circuit terminal outside of said housing and each having a support extending into said housing, spring-pressed members hinged to the respective supports and each spring-pressed member being biased to engage the other spring-pressed member in the closed circuit position, overload means coacting with one of said hinged members for actuating it to break the circuit on an overload and manually operable spring-retracted means coacting with the other hinged member for actuating it to reclose the circuit.

' BENJAMIN E. GETCHELL.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,527,645 Hall Feb. 24, 1925 1,726,503 Platt Aug. 27, 1929 2,147,754 Rivers Feb. 21, 1939 2,168,180 Townsend Aug. 1, 1939 2,205,944 Dunmire June 25, 1940 2,276,366 Barrett n", Mar. 17, 1942 

